Gnuplot comes with a large collection of demonstration plots.
You can step through these interactively by typing the command below in
gnuplot's demo/ directory  it should be part of your installation,
otherwise get it from the
source code archive
or file-by-file from the
git repository.

gnuplot> load "all.dem"

Hint: you can get a single big postscript file of all the demo plots by the
following sequence of commands